Method of cutting a slaughtered bird from vent to breast

ABSTRACT

A method for eviscerating a slaughtered bird, starting from the vent and directed toward the breast point, comprising first making a circular opening at the vent of the bird using a first knife and starting a second cut in the bird by moving a second knife from the circular opening along a path offset from a straight line between the vent and the breast point avoiding cutting of the entrails of the bird located below the straight line. Preferentially, the respective knives are removed from the carcass immediately after the respective cuts are made successively, the second knife retracing its path back to the circular opening before removal.

This is a division of application Ser. No. 10,233 filed Feb. 8, 1979,now U.S Pat. No. 4,266,322.

BACKGROUND OF THE INVENTION

The invention relates to a method of making a cut extending from thevent toward the breast in slaughtered birds, a first, round cut beingmade around the vent followed by a second cut starting therefrom anddirected toward the breast of the bird.

The invention furthermore relates to a device for making a cut inslaughtered birds extending from the vent toward the breast, the devicecomprising a knife mounted in a frame and traveling with its cuttingedge, along the path of a circle while being capable of being drivenrotatably, and in the vicinity thereof disposed in a holder, a secondknife capable of moving in a direction away from the first knife, thepath of the holder being determined by the movement of at least one camconnected thereto traveling in a non-linear guideway.

DISCUSSION OF THE PRIOR ART

A method and device as described above are known per se. According tosaid known method and device, the cutting knife, starting from theannular opening made around the vent, travels in a straight path to thechest bone. Hereby the danger exists that the knife point will touchparts of the entrails section, in particular intestines, thuscontaminating the bird's meat with the contents thereof, so that thebird must be rejected. Dutch Patent Application No. 75,13767, laid opento public inspection, already proposes a device whose object it is toobviate this drawback, but it is relatively complicated: in this devicea hollow ball connected to the cutting knife is used which can bedivided into two halves which can be moved independently of one anotherby means of a suitable driving mechanism; after bringing the ball insidethe bird, the ball divides into two parts whereupon one ball half pushesthe entrails to the side while the knife makes the cut.

SUMMARY OF THE INVENTION

The present invention is based upon the insight that the effect aimedat, i.e. preventing damage to the entrails, is obtainable in a simplemanner, merely by making a proper choice of the path of the knife.Consequently, the method of the invention is carried out in such amanner that, while making the second cut, the cutting edge during itsmovement away from the vent is caused to make a sideward movement overat least a part of its travel such, that the cutting edge moves asidethe area comprising the entrails.

This measure, which hardly makes a device for making this cut morecomplicated, effectively ensures that when making the cut the cuttingedge of the knife cannot come into contact with the entrails.

In a device for carrying out the method as described hereinbefore theknife-holding arm is rotatably disposed in a holder and is provided, atits end opposite the knife, with the guide cam, the latter holder beingpivotally connected about an axis crossing the axis of the knife-holdingarm, being connected to a connecting rod pivoting in the frame andcoupled to driving means adapted to carry out a backward-and-forwardswinging movement.

The track of the guideway is then such that during the movement directedtoward the breast point the cutting knife, starting from the round cutmade by the rotating knife, initially carries out a movement directedsideways away from the connecting line between the vent and the breastpoint, followed by a movement directed toward said connecting line.

A very simple embodiment is obtained when the oblong knife-holding armis hook-shaped having a short first part receiving the cutting knife anda second part located in the holder, the end protruding from the holderbeing provided with the guide cam, and the hinge joint of the holder andconnecting rod being located between the flanged end and said guide cam.

The second part of the knife-holding arm located in the holder iscylindrical and supported in one or more bearing bushings located in theholder.

A favorable embodiment is obtained when the frame is provided with atleast one guide plate which is located perpendicularly to the axes ofthe hinge joints of the connecting rod and parallel to the path of theholder comprising the guideway receiving the cam.

This measure has the advantage that the path of the knife is fullydetermined by the pattern of the guide slot in both a vertical and ahorizontal direction, and that the device can be easily adapted todifferent dimensions and kinds of birds by using a plate with adifferent profile.

Preferably, the knife-holding arm is provided with two aligned camsprotruding on both sides, each one co-operating with a correspondingguideway formed in each of the two parallel guideplates.

A favorable embodiment enabling a high production rate comprises a frameprovided with positioning elements for the birds being arranged togetherwith a number of corresponding frames in a circle and rotatable about acentral shaft in a common framework to be placed at a cutting locusalong a conveyor for slaughtered birds by which the birds aretransported hanging by their legs, to be driven in synchronism with theconveyor.

SURVEY OF THE DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of a treatment unit of thedevice according to the invention;

FIG. 2 is an enlarged view of the most important parts of this device,in particular the knife-holding arm;

FIG. 3 is a front view of the device according to the invention;

FIG. 4 is a top view of this device;

FIG. 5a is a lateral view of the first guide plate;

FIG. 5b is a lateral view of the second guide plate.

DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows a central shaft 1, about which a number of treatment unitsare rotatably arranged, one of which being indicated in its entirety bythe reference numeral 2. The treatment units rotate about said shaft insynchronism with a moving conveyor 3 known per se, to which, by way ofthe suspension rods 4 schematically indicated, there are suspended theknown hooks 5, by which the birds 6, hooked into the hook openings bytheir legs, are transported. As is known in the art, the varioustreatment functions and movements are controlled by the movement ofdetents and cams of each unit along stationary guideways, not shown indetail. The complete device comprises a number, depending upon thecapacity desired, of for example, sixteen to twenty units arranged atregular distances around the central shaft 1 and of the type asillustrated; the movements of the conveyor and that of the treatmentunits are adjusted to each other and synchronized in a manner such, thatthe birds are introduced into a treatment unit, are clamped therein,remain in the treatment unit during the treatment (making the cut),while simultaneously traveling in a circular, curved path, andsubsequently leaving the unit. FIG. 1 shows a number of frames 7 to 12inclusive of which the frames 10 and 12, provided with guideways, arestationary and the frame 7 to 9 inclusive and 11 rotate jointly aroundthe shaft 1. The frames 9 and 11 support an operating unit 13, the rod14 of which is driven both rotatably and vertically by driving means,not shown, while holding at its lower extremity the round cutting knife15 with the guide pin 16. This known combination of cutting knife 15 andthe guide pin 16 serves to make a round cut around the arse from wherethe cut directed toward the breast point is to be made. During thistreatment the bird is secured in position between the fixed detent 17and the movable detent 18 which can turn around the pin 19 and whosedriving cam 20 co-operates with the curved track 12a. During treatmentthe hook 5 is in the pulled-up position as drawn. In the position 5a ofthe hook, the hook with the bird hanging thereon will not pass throughthe device but instead will go around it on the outside, because theside of the hook will run against the guideway 21. The bird is drawn inthe Figure in the treatment position. The tail is then pressed backwardsby the detent 18a. In FIG. 2, which is an enlarged view of the elementsof importance to the invention, the discontinuous lines 18a indicate theposition of the movable detent 18 for introducing the bird into thetreatment unit; continuous lines indicate in this Figure the positionduring the treatment.

The elements of importance to the invention are formed by the cuttingknife for making the cut running from the round cut made in the venttoward the breast point, and the special actuating elements therefor.

FIG. 2 shows the vertical support 21, which is connected to a frame 11and which supports the pivotal detent 18, and wherein, at a distanceupwards from the point of rotation 19, the pivot 22 supports theconnecting rod 23 with the operating arm 24a fixedly connected theretohaving an operating cam 25 which cooperates with a guideway not shown inthe drawing. The whole device has been arranged in such a manner thatwhen carrying out the rotary movement around the central shaft 1, at agiven moment when the bird has been clamped in, the guideway pushes theguide cam 25 upwards so that the rod 23 shifts from the positionindicated by the discontinuous line. At the extremity of the rod 23there is pivotally connected with the pivot 24 the knife holder 25a withthe guide bushings 26, 27, wherein there is disposed rotatably about theaxis 28 the cylindrical knife-holding arm 29 whose hook-shaped end 30holds at the front edge the cutting knife 31. The lower end of thehook-shaped end 30 is, as indicated by the reference numeral 32, roundedand so cannot cause damage to the entrails when moving back. In itsmovement the knife 31 has to travel along a complicated path: from thestarting position as shown in FIG. 2 with the continuous line, to thefinal position as drawn with the discontinuous line, the point of theknife moves, as indicated by the discontinuous line 33 in FIG. 2, notonly first downwards and thereupon upwards again (path sections 33a,33b, 33c), but also, as indicated by the discontinuous line 34 in FIG.4,--which Figure is partly a plain and partly a cross-sectional view ofthe upper part of the unit shown in FIG. 2--the cutting edge of theknife 31, which in the starting position as viewed from above is on theright-hand side of the line 35 whose point of intersection with the line35 a indicates the center of the vent, first has to make a movementdirected toward the line 35 (line section 34a), subsequently a swiftmovement directed away from the line 35 (line section 34b), then asomewhat diverging movement (line section 34c), thereupon again a swiftmovement directed towrad the line 35 (line section 34d) followed by amovement running practically parallel to the line 35 (line section 34e).Finally, in the position as drawn by the dotted line 31a, the knifecomes to a momentary rest; when the movements proceed again, the pathdescribed above is traveled in the reverse direction.

The advantage of this special path of the knife, which is essential tothe device of this invention, is the fact that, when making the cutdeparting from the circular vent cut and directed toward the breastpoint, the cutting edge of the knife moves around the area containingthe entrails (line sections 34b, 34c, 34d), thus preventing anypossibility of damaging the entrails and subsequent disadvantages(contamination of the bird's meat and subsequent rejection thereof).

Bringing about this particular path pattern is, of course, possible invarious ways, but the invention proposes a very effective andtechnically simple solution, having the advantage that it is possible toobtain any desired path pattern by simply exchanging two parts. Theseparts are formed by the end plates 36, 37 secured with screws 38 to thesides of a substantially U-shaped frame 39, whose downwardly extendingsupporting part 40 is attached to the frame 11, jointly with the framepart 21, by means of the screws 41, 41a. On one side the space withinthe U-shaped frame 39 is closed off by the end plate 36 and on the otherside by the end plate 37. As shown in FIGS. 5a and 5b, each of theplates 36 and 37 is provided with a guide slot 42 and 43 respectively,which have different patterns with respect to each other; this slot isadapted to receive the guide pin 44 located at the end of thecylindrical knife-holding arm 29. When the connecting rod 23 moves fromthe position indicated by the continuous line to the position indicatedby the discontinuous line, said two slots in combination determine thepivoting of the knife holder 25a about the pivot 24, and thus thedownwardly directed movement of the point of the knife 31 (as indicatedby the line 33 in FIG. 2) as well as the rotation of the cylindricalknife-holding rod 29 about the axis 28 and thus the path of travel ofthe cutting knife 31 in the horizontal plane, as indicated by the line34 in FIG. 4. In order to obtain the desired path-complicated-the slot42 has a rising portion 42a, a relatively long, initially somewhatdescending and then rising portion 42b followed by a steeply risingportion 42c, with which a portion 42d is vertically associated at anangle of about 45°. The slot 43 comprises a rising portion 43a, a curvedportion 43b with a relatively large radius of curvature and a relativelysteeply descending portion 43c.

The advantage of the driving means of the knife described above is that,since the guide plates determine both the vertical and the horizontalmovements of the knife by exchanging said plates for plates having slotswith different patterns, the device can be quickly adapted in a simplemanner to the birds to be treated, since the depth of the cut as well asthe path of the knife in a horizontal direction, can be chosen asdesired. The guide plates may consist of a wear-resistant syntheticmaterial requiring little maintenance, while in addition they providesome protection against humidity to the knife-holder mechanism soenclosed.

Several elements not essential to the present invention have not beendiscussed in the above description; when being introduced into atreatment unit, the hook 5 will, naturally have to be guided, for whichpurpose it is possible to employ guideways such as the guideway 21 andthe guideway 45, and the hook puller 46. The knife may be a cuttingknife known per se, for instance a "Stanley" product, that, in an easilyexchangeable manner, may be fitted into the hook-shaped portion 30 ofthe knife-holding arm.

What is claimed is:
 1. A method of cutting open a slaughtered birdbetween its vent and breast point while the bird is moving along aconveyor which comprisesA. cutting a circular opening at the vent of thebird as a first cut, said opening having its axis aligned with astraight line from the vent to the breast point, B. starting a secondcut in the bird at the circular opening and extending toward the breastpoint along said axis, C. continuing the second cut along a portion ofthe cut that is laterally offset from said line between the vent andbreast point by a predetermined lateral distance so as to avoid cuttingcertain entrails located within the bird below said straight line and D.completing the second cut in a movement back to said breast point. 2.The method as claimed in claim 1 in which said knives are movedsynchronously with the bird movement on said conveyor while making saidcuts.
 3. The method as claimed in claim 1 or 2 in which the circularopening is made with a circular knife, the cutting comprising rotatingand entering the bird with said circular knife followed by removal ofsaid knife, the second cut being made by a relatively planar blade knifewhich traces the complete path of the second cut.
 4. A method of cuttingopen a slaughtered bird between its vent and breast point while the birdis moving along a conveyor which comprisesA. cutting a circular openingat the vent of the bird as a first cut by rotating a circular knife andentering the bird with said circular knife followed by removal of saidknife, B. starting a second cut in the bird at the circular opening andextending toward the breast point using a relatively planar blade knife,C. completing the second cut along a path that is laterally offset froma straight line between the vent and breast point using said relativelyplanar blade knife to trace the complete path of said second cut so asto avoid cutting certain entrails located within the bird below saidstraight line, and D. removing the blade knife from the bird aftermaking the second cut.
 5. A method of making a cut in a slaughtered birdextending from the vent to the breast point of the bird while the birdis moving along a conveyor which comprisesA. inserting a rotary knifeinto the bird at the vent, cutting a circular opening at the vent andremoving the rotary knife, B. inserting a second knife having arelatively planar blade into said circular opening and moving the secondknife toward the breast point while cutting the bird's skin in a pathwhich makes a second cut while the second knife is carried along a pathlaterally displaced from a direct line between the vent and breast pointso as to avoid cutting certain entrails of the bird, and C. thereafterremoving the second knife from the bird.
 6. The method as claimed inclaim 4 or 5 in which the blade knife is removed from the bird onlyafter the blade has been reversed in its movement from vent towardbreast point and has retraced the path of the second cut to the circularopening.
 7. The method as claimed in claim 5 in which the second knifeis moved back to said circular cut after having made the second cutalong said path and is removed from said bird at said circular cut. 8.The method as claimed in claims 4 or 5 in which the knives are movedsynchronously with the bird movement on the conveyor while making saidcuts.